1. Field of the Invention
The present invention relates to an imaging optical lens system, and more particularly, to an imaging optical lens system used in compact electronic products and 3D applications thereof.
2. Description of the Prior Art
The principal demand of modern electronic products is compact and portable; therefore, apart from reducing manufacture costs, the requirement of being compact and portable is essential for the optical systems on today's various portable electronics such as smart phones, tablets, Ultrabooks, etc. As an optical system disclosed in U.S. Pat. No. 7,957,076, conventional optical systems tend to have only two lens elements for reducing manufacture costs; however, the aberration correction ability thereof is limited as the two-lens-element optical system fails to satisfy higher demand in image quality.
On the other hand, the four-lens-element lens system, such as the one disclosed in U.S. Pat. No. 8,089,704 B2, is not compact enough as too many lens elements are allocated, and the costs and the manufacture complexity are relatively higher. In addition, the three-lens-element system disclosed in U.S. Pat. No. 8,094,231 B2 has limited imaging performance and quality due to deficiency of defocus resulting from serious off-axis aberration. Moreover, the configuration of the optical system fails to reduce the back focal length thereof and results the optical system being larger than desired.
In light of the foregoing, conventional optical systems have drawbacks of undesirable imaging quality and excessively long total track length that are not suitable for compact portable electronics. It is therefore well-known that the issue of obtaining a favorable balance between image quality and total track length has existed in the field. Therefore, there is a need for an imaging system having superior image quality and compact design for space usage in the system, which is suitable for portable electronics.